Methods for recovering copper from bismuth concentrate

Abstract

This invention provides a method for recovering copper from bismuth concentrate. The initial bismuth concentrate is slurried with water without additional reagents. Residual collectors and other reagents from the upstream flotation process are used to de-sludge the initial bismuth concentrate using flotation. The residue at the bottom of the flotation cell is the removed slime. The frothy product obtained from flotation is then subjected to copper-bismuth separation roughing. The resulting rough concentrate undergoes copper-bismuth separation fine-roughing to obtain fine-rough concentrate and fine-rough tailings. The fine-rough concentrate is then subjected to two closed-circuit cleaning processes to obtain copper concentrate, and the fine-rough tailings are subjected to two closed-circuit scavenging processes to obtain tailings. This invention, targeting copper-bismuth concentrate, employs measures such as "flotation de-sludge removal, strong alkali + highly efficient and environmentally friendly bismuth inhibitor CD-B1 combination to suppress bismuth minerals, and enhanced selective recovery of copper minerals." These measures significantly improve the copper-bismuth separation flotation environment, increase the efficiency of "bismuth-suppressed copper flotation," and achieve effective separation and recovery of low-grade copper from bismuth concentrate.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and more particularly to a method for recovering copper from bismuth concentrate. Background Technology

[0002] Bismuth polymetallic ores with a copper content of less than 0.1% are an important associated copper resource. Currently, the main beneficiation process basically adopts the method of "sulfide ore mixed flotation - polymetallic step separation flotation", with copper metal mostly concentrated in bismuth concentrate (containing 2% to 3% copper). Due to the good natural floatability of both copper minerals (mainly chalcopyrite) and bismuth minerals (mainly bismuthite), their flotation separation is quite difficult. The technical solutions are mainly divided into "copper suppression for bismuth flotation" and "bismuth suppression for copper flotation". The former usually requires the addition of cyanide, which is seriously harmful to the environment and has been gradually phased out. The latter, as the most important copper-bismuth separation method, mainly focuses on developing efficient and environmentally friendly bismuth inhibitors, and further improvements are needed in terms of copper-bismuth separation effect and technical stability.

[0003] Copper and bismuth minerals differ in specific gravity and specific magnetic susceptibility, and theoretically, they can be separated by gravity separation or strong magnetic separation. However, most copper and bismuth minerals exist in the -0.037mm particle size, making it difficult to achieve good separation results by gravity separation in practical applications. Copper and bismuth concentrates separated by strong magnetic separation are prone to mutual inclusion exceeding the standard, resulting in poor copper concentrate quality, and the investment in strong magnetic separation equipment is large.

[0004] Patent CN106238202A discloses an ultrasonic dispersion-magnetic separation process for copper-bismuth mixed concentrates. While this method achieves good results, it suffers from complex procedures and environmental pollution caused by ultrasonic waves. Furthermore, it is primarily suitable for copper-bismuth mixed concentrates with a high copper content and low bismuth content; its applicability to copper-bismuth mixed concentrates with a low copper content and high bismuth content is currently unclear. Therefore, there is a need to develop more efficient beneficiation processes and more economical and environmentally friendly bismuth inhibitors and reagent systems for copper-containing bismuth concentrates to significantly improve the recovery of low-grade copper resources associated with bismuth polymetallic ores.

[0005] In view of this, it is necessary to design an improved method for recovering copper from bismuth concentrate to solve the above problems. Summary of the Invention

[0006] To address the shortcomings of the existing technology, the present invention aims to provide a method for recovering copper from bismuth concentrate. Based on the difference in floatability between copper and bismuth minerals, the method utilizes residual reagents from the front-end flotation operation for pre-flotation desliming, improving the flotation environment for subsequent "bismuth suppression and copper flotation" operations and reducing separation difficulty. The method employs a "roughing and tailings discharge - fine and enhanced separation" process flow and a "strong alkali + combined reagents synergistic inhibition of bismuth minerals - enhanced selective recovery of copper minerals" reagent system to achieve efficient copper separation and recovery, effectively solving the technical problem of copper-bismuth separation in copper-bismuth concentrate.

[0007] To achieve the above objectives, the present invention provides a method for recovering copper from bismuth concentrate, comprising the following steps:

[0008] S1. Adjust the initial bismuth concentrate to a pulp concentration of 15-20%, and use flotation to de-dry and remove reagents from the initial bismuth concentrate. The removed mud is obtained at the bottom of the flotation cell, which is the first bismuth concentrate, and the froth product is obtained at the top.

[0009] S2. Add desiccant, pH adjuster, bismuth inhibitor, copper collector and foaming agent to the foam product obtained in step S1 in sequence, and perform copper-bismuth separation roughing to obtain roughing concentrate and roughing tailings, wherein the roughing tailings are second bismuth concentrate;

[0010] S3. Add pH adjuster, bismuth inhibitor and copper collector to the rough concentrate obtained in step S2 in sequence to carry out copper-bismuth separation rough and fine separation to obtain fine and fine concentrate and fine and fine tailings;

[0011] S4. The fine and rough concentrate obtained in step S3 is sequentially added with pH adjuster and bismuth inhibitor to perform a first cleaning operation, resulting in a first clean concentrate and a first clean tailings; the first clean concentrate is sequentially added with pH adjuster and bismuth inhibitor to perform a second cleaning operation, resulting in a copper concentrate and a second clean tailings, and the second clean tailings are returned to the first cleaning operation;

[0012] S5. Add a copper collector to the tailings obtained in step S3 and perform a first scavenging operation to obtain a first scavenging concentrate and a first scavenging tailings; add a copper collector to the first scavenging tailings and perform a second scavenging operation to obtain a second scavenging concentrate and a second scavenging tailings, wherein the second scavenging tailings is a third bismuth concentrate; return the second scavenging concentrate to the first scavenging operation;

[0013] S6. Combine the first fine tailings described in step S4 and the first scavenging concentrate described in step S5 and return them to the fine and roughing operation in step S3.

[0014] As a further improvement of the present invention, the desiccant is activated carbon, the pH adjuster is calcium oxide, the bismuth inhibitor is CD-B1, the copper collector is ethyl thiocyanate, and the foaming agent is F6.

[0015] As a further improvement of the present invention, in step S2, the dosage of the desiccant is 1000-4000 g / t; the dosage of the pH adjuster is 10000-20000 g / t; the dosage of the bismuth inhibitor is 2000-8000 g / t; the dosage of the copper collector is 50-200 g / t; and the dosage of the foaming agent is 10-50 g / t.

[0016] As a further improvement of the present invention, in step S3, the amount of the pH adjuster is 6000-8000 g / t, the amount of the bismuth inhibitor is 1000-5000 g / t, and the amount of the copper collector is 10-100 g / t.

[0017] As a further improvement of the present invention, in step S4, the amount of pH adjuster added in the first selection operation is 2000-6000 g / t, and the amount of bismuth inhibitor is 500-2000 g / t.

[0018] Furthermore, the amount of pH adjuster added in the second refining operation is 1000-3000 g / t, and the amount of bismuth inhibitor is 100-1000 g / t.

[0019] As a further improvement of the present invention, in step S5, the amount of copper collector added in the first scavenging operation is 10-50 g / t, and the amount of copper collector added in the second scavenging operation is 5-20 g / t.

[0020] As a further improvement of the present invention, the initial bismuth concentrate contains 2-3% copper and 30-35% bismuth.

[0021] As a further improvement of the present invention, CD-B1 is obtained by mixing sodium metabisulfite, sodium sulfite, sodium carboxymethyl cellulose and sodium starch phosphate in a mass percentage ratio of 20-30%: 20-25%: 30-40%: 10-15%.

[0022] As a further improvement of the present invention, F6 is obtained by mixing and compounding terpenoid alcohol, isobutanol and isoamyl alcohol in a mass percentage ratio of 50-60%: 10-20%: 25-35%.

[0023] The beneficial effects of this invention are:

[0024] 1. This invention provides a method for recovering copper from bismuth concentrate. The initial bismuth concentrate is slurried with water without additional reagents. Residual collectors and other reagents from the upstream flotation process are used to de-sludge the initial bismuth concentrate using flotation. The residue at the bottom of the flotation cell is the removed slime. The frothy product obtained from flotation is then subjected to copper-bismuth separation roughing. The resulting rough concentrate undergoes copper-bismuth separation fine-roughing to obtain fine-rough concentrate and fine-rough tailings. The fine-rough concentrate is then subjected to two closed-circuit cleaning processes to obtain copper concentrate, and the fine-rough tailings are subjected to two closed-circuit scavenging processes to obtain tailings. This invention, targeting copper-bismuth concentrate, employs measures such as "flotation de-sludge removal, strong alkali + highly efficient and environmentally friendly bismuth inhibitor CD-B1 combination to suppress bismuth minerals, and enhanced selective recovery of copper minerals." These measures significantly improve the copper-bismuth separation flotation environment, increase the efficiency of "bismuth suppression and copper flotation," and achieve effective separation and recovery of low-grade copper from bismuth concentrate.

[0025] 2. Based on the characteristics of copper-bismuth concentrate, this invention effectively utilizes the residual reagents in the front-end flotation operation and the initial floatability differences between copper and bismuth minerals. By leveraging the collecting and foaming effects of the residual reagent system, the reagents (mud) are pre-flotated and pre-enriched, with most of the copper (accounting for approximately 90% of the total copper metal) and some of the bismuth (accounting for approximately 30% of the total bismuth metal) removed, thus creating conditions for achieving good indicators in the subsequent "bismuth suppression and copper flotation".

[0026] 3. Under the premise of ensuring copper beneficiation recovery rate, this invention adopts the process flow of "roughing and tailings discharge - fine and enhanced separation". In the roughing operation of copper-bismuth separation, most of the bismuth minerals are quickly discharged, achieving the separation purpose of "early rejection and early recovery". At the same time, it effectively reduces the amount of middlings recycling, significantly improves the efficiency of "bismuth suppression and copper flotation" operation, and improves the adaptability and stability of the process.

[0027] 4. This invention uses activated carbon for secondary enhanced decanting, CD-B1 high-efficiency and environmentally friendly bismuth inhibitor forms a high-alkali inhibition system with calcium oxide, and ethyl thiocyanate + F6 combined collecting and foaming system, which effectively expands the difference in floatability between copper and bismuth minerals, achieving high-efficiency inhibition of bismuth minerals and high-selectivity recovery of copper minerals, providing key support for "bismuth suppression and copper floating".

[0028] 5. This invention effectively solves the problem of difficult copper recovery from copper-bismuth concentrate. The process is simplified and reliable, and the reagent system is efficient and environmentally friendly, providing a new and effective method for the recovery of similar associated copper resources. Attached Figure Description

[0029] Figure 1 This is a flowchart of a method for recovering copper from bismuth concentrate according to Embodiment 1 of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0032] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0033] This invention provides a method for recovering copper from bismuth concentrate, comprising the following steps:

[0034] S1. Adjust the initial bismuth concentrate to a pulp concentration of 15-20%, and use flotation to remove reagents and mud from the initial bismuth concentrate. The mud removed at the bottom of the flotation cell is the first bismuth concentrate, and the froth product is obtained at the top.

[0035] Specifically, the initial bismuth concentrate is mixed with water to form a slurry, without adding any additional reagents. The initial bismuth concentrate is then deslimed using flotation with the collectors and other reagents remaining from the initial flotation operation. These remaining collectors and other reagents are common bismuth and copper flotation reagents, consisting of one or more of the following: xanthates, diammonium phosphates, sulfur-nitrogen compounds, sulfur amino esters, hydrocarbon oils, and pine oil.

[0036] By mass percentage, the initial bismuth concentrate contains 2-3% copper (mainly chalcopyrite) and 30-35% bismuth (mainly bismuthite).

[0037] S2. Add desiccant, pH adjuster, bismuth inhibitor, copper collector and foaming agent to the foam product obtained in step S1 in sequence, and perform copper-bismuth separation roughing to obtain roughing concentrate and roughing tailings. The roughing tailings are the second bismuth concentrate.

[0038] Specifically, the desiccant is activated carbon, with a dosage of 1000–4000 g / t; the pH adjuster is calcium oxide, with a dosage of 10000–20000 g / t; the bismuth inhibitor is CD-B1, with a dosage of 2000–8000 g / t; the copper collector is ethyl thiocyanate, with a dosage of 50–200 g / t; and the foaming agent is F6, with a dosage of 10–50 g / t.

[0039] CD-B1 is an environmentally friendly and highly efficient bismuth inhibitor composed of inorganic and high-molecular-weight organic compounds. Specifically, it is prepared by mixing sodium metabisulfite, sodium sulfite, sodium carboxymethyl cellulose, and sodium starch phosphate in a mass percentage ratio of 20-30%, 20-25%, 30-40%, and 10-15%.

[0040] F6 is a highly selective foaming agent composed of a combination of various alcohols, specifically a mixture of terpenoid alcohol, isobutanol, and isoamyl alcohol in a mass percentage ratio of 50-60%, 10-20%, and 25-35%.

[0041] S3. Add pH adjuster, bismuth inhibitor and copper collector to the rough concentrate obtained in step S2 in sequence to carry out copper-bismuth separation rough and fine separation to obtain fine and rough concentrate and fine and rough tailings.

[0042] Specifically, the dosage of pH adjuster is 6000-8000 g / t, the dosage of bismuth inhibitor is 1000-5000 g / t, and the dosage of copper collector is 10-100 g / t.

[0043] S4. The fine and rough concentrates obtained in step S3 are sequentially added with pH adjuster and bismuth inhibitor to perform a first cleaning operation, resulting in a first clean concentrate and a first clean tailings; the first clean concentrate is sequentially added with pH adjuster and bismuth inhibitor to perform a second cleaning operation, resulting in a copper concentrate and a second clean tailings, and the second clean tailings are returned to the first cleaning operation.

[0044] Specifically, in the first purification process, the amount of pH adjuster added is 2000–6000 g / t, and the amount of bismuth inhibitor added is 500–2000 g / t. In the second purification process, the amount of pH adjuster added is 1000–3000 g / t, and the amount of bismuth inhibitor added is 100–1000 g / t.

[0045] S5. Add a copper collector to the tailings obtained in step S3 and perform a first scavenging operation to obtain a first scavenging concentrate and a first scavenging tailings; add a copper collector to the first scavenging tailings and perform a second scavenging operation to obtain a second scavenging concentrate and a second scavenging tailings, wherein the second scavenging tailings is a third bismuth concentrate; return the second scavenging concentrate to the first scavenging operation.

[0046] Specifically, the amount of copper collector added in the first scavenging operation is 10-50 g / t, and the amount of copper collector added in the second scavenging operation is 5-20 g / t.

[0047] S6. Combine the first fine tailings described in step S4 and the first scavenging concentrate described in step S5 and return them to the fine and roughing operation in step S3.

[0048] The method for recovering copper from bismuth concentrate provided by the present invention will be described below with reference to specific embodiments.

[0049] Example 1

[0050] Example 1 provides a method for recovering copper from bismuth concentrate, such as... Figure 1 As shown, it includes the following steps:

[0051] S1. The initial bismuth concentrate is mixed with water to a pulp concentration of 15%. No additional reagents are added. Using the collectors and other reagents remaining from the upstream flotation operation, the initial bismuth concentrate is de-removed (sludge) by flotation. The residue at the bottom of the flotation cell is the removed sludge, which is the first bismuth concentrate. Figure 1 The bismuth concentrate is represented as 1).

[0052] S2. The froth product obtained from flotation in step S1 is sequentially supplemented with 2000 g / t activated carbon (de-removing agent), 15000 g / t calcium oxide (pH adjuster), 5000 g / t CD-B1 (bismuth inhibitor), 100 g / t ethyl thiocyanate (copper collector), and 30 g / t frother F6 for copper-bismuth separation roughing to obtain roughing concentrate and tailings 1. Tailings 1 is the second bismuth concentrate. Figure 1 The middle part is represented as bismuth concentrate 2); CD-B1 is obtained by mixing sodium metabisulfite, sodium sulfite, sodium carboxymethyl cellulose and sodium starch phosphate in a mass percentage of 25%:25%:35%:15%; F6 is obtained by mixing terpene alcohol, isobutanol and isoamyl alcohol in a mass percentage of 55%:15%:30%;

[0053] S3. For the rough concentrate obtained in step S2, add 7000g / t of calcium oxide, 2000g / t of bismuth inhibitor CD-B1, and 60g / t of ethyl thiocyanate in sequence to carry out copper-bismuth separation and fine-rough separation to obtain fine-rough concentrate and fine-rough tailings.

[0054] S4. The copper concentrate obtained in step S3 is further processed through two closed-circuit cleaning operations to obtain copper concentrate. In cleaning operation 1, 4000 g / t of calcium oxide and 1000 g / t of bismuth inhibitor CD-B1 are added sequentially; in cleaning operation 2, 2000 g / t of calcium oxide and 500 g / t of bismuth inhibitor CD-B1 are added sequentially. The tailings from cleaning operation 2 are returned to cleaning operation 1.

[0055] S5. The tailings obtained in step S3 are subjected to two closed-circuit scavenging processes to obtain tailings 2, namely the third bismuth concentrate. Figure 1 The sample is designated as bismuth concentrate 3). Ethyl thiocyanate 30 g / t is added to scavenging operation 1, and ethyl thiocyanate 10 g / t is added to scavenging operation 2. The concentrate from scavenging operation 2 is returned to scavenging operation 1.

[0056] S6. Combine the tailings from the fine separation operation 1 in step S4 and the concentrate from the scavenging operation 1 in step S5 and return them to the fine and rough separation operation in step S3.

[0057] The experimental data obtained in this embodiment are shown in Table 1.

[0058] Table 1 Test Results of Example 1

[0059]

[0060]

[0061] Comparative Example 1

[0062] Comparative Example 1 provides a method for recovering copper from bismuth concentrate. Compared with Example 1, the only difference is that the flotation desliming (sludge) operation in step S1 is omitted. Other experimental parameters and conditions are basically the same as in Example 1 and will not be repeated here. The experimental data obtained are shown in Table 2. It can be seen that the copper recovery effect is poor, and a lot of bismuth is lost in the copper concentrate. This indicates that the flotation desliming (sludge) step plays a key role in the recovery of copper from bismuth concentrate. Without the flotation desliming (sludge) operation, impurities and fine mud are not effectively removed, affecting the flotation effect of copper. Bismuth and other valuable metals may not be effectively separated due to the interference of fine mud, resulting in the loss of bismuth in the copper concentrate.

[0063] Table 2 shows the test results of Comparative Example 1.

[0064]

[0065] Comparative Example 2

[0066] Comparative Example 2 provides a method for recovering copper from bismuth concentrate. Compared to Example 1, the only difference is that CD-B1 was not added in steps S2, S3, and S4. Other experimental parameters and conditions are basically the same as in Example 1 and will not be repeated here. The experimental data obtained are shown in Table 3. It can be seen that the copper recovery effect is poor, and a significant amount of bismuth is lost in the copper concentrate. Because CD-B1 was not added, the bismuth minerals were not effectively suppressed, resulting in the recovery of bismuth minerals along with copper minerals during flotation, increasing the loss of bismuth in the copper concentrate. The mixing of bismuth minerals and copper minerals leads to a decrease in flotation selectivity, thereby affecting the copper recovery rate.

[0067] Table 3. Test results of Comparative Example 2

[0068]

[0069] In summary, this invention targets copper-bismuth concentrates and employs measures such as "flotation descaling (sludge), strong alkali + high-efficiency and environmentally friendly bismuth inhibitor CD-B1 combination to suppress bismuth minerals, and enhanced selective recovery of copper minerals." These measures significantly improve the copper-bismuth separation flotation environment, increase the flotation efficiency of "bismuth suppression and copper flotation," and achieve effective separation and recovery of low-grade copper in bismuth concentrates.

[0070] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for recovering copper from bismuth concentrate, characterized in that, Includes the following steps: S1. Adjust the initial bismuth concentrate to a pulp concentration of 15-20%, and use flotation to de-dry and remove reagents from the initial bismuth concentrate. The removed mud is obtained at the bottom of the flotation cell, which is the first bismuth concentrate, and the froth product is obtained at the top. S2. The foam product obtained in step S1 is sequentially supplemented with a desiccant, a pH adjuster, a bismuth inhibitor, a copper collector, and a foaming agent to perform copper-bismuth separation roughing to obtain a roughing concentrate and roughing tailings, wherein the roughing tailings are a second bismuth concentrate; the desiccant is activated carbon, the pH adjuster is calcium oxide, the bismuth inhibitor is CD-B1, the copper collector is ethyl thiocyanate, and the foaming agent is F6; The CD-B1 is obtained by mixing and compounding sodium metabisulfite, sodium sulfite, sodium carboxymethyl cellulose and sodium starch phosphate in a mass percentage ratio of 20~30%: 20~25%: 30~40%: 10~15%. The F6 is obtained by mixing and compounding terpenoid alcohol, isobutanol, and isoamyl alcohol in a mass percentage ratio of 50-60%: 10-20%: 25-35%. S3. Add pH adjuster, bismuth inhibitor and copper collector to the rough concentrate obtained in step S2 in sequence to carry out copper-bismuth separation rough and fine separation to obtain fine and fine concentrate and fine and fine tailings; S4. The fine and rough concentrate obtained in step S3 is sequentially added with pH adjuster and bismuth inhibitor to perform a first cleaning operation, resulting in a first clean concentrate and a first clean tailings; the first clean concentrate is sequentially added with pH adjuster and bismuth inhibitor to perform a second cleaning operation, resulting in a copper concentrate and a second clean tailings, and the second clean tailings are returned to the first cleaning operation; S5. Add a copper collector to the tailings obtained in step S3 and perform a first scavenging operation to obtain a first scavenging concentrate and a first scavenging tailings; add a copper collector to the first scavenging tailings and perform a second scavenging operation to obtain a second scavenging concentrate and a second scavenging tailings, wherein the second scavenging tailings is a third bismuth concentrate; return the second scavenging concentrate to the first scavenging operation; S6. Combine the first fine tailings described in step S4 and the first scavenging concentrate described in step S5 and return them to the fine and roughing operation in step S3.

2. The method for recovering copper from bismuth concentrate according to claim 1, characterized in that, In step S2, the dosage of the desiccant is 1000~4000 g / t; the dosage of the pH adjuster is 10000~20000 g / t; the dosage of the bismuth inhibitor is 2000~8000 g / t; the dosage of the copper collector is 50~200 g / t; and the dosage of the foaming agent is 10~50 g / t.

3. The method for recovering copper from bismuth concentrate according to claim 1, characterized in that, In step S3, the amount of pH adjuster is 6000~8000 g / t, the amount of bismuth inhibitor is 1000~5000 g / t, and the amount of copper collector is 10~100 g / t.

4. The method for recovering copper from bismuth concentrate according to claim 1, characterized in that, In step S4, the amount of pH adjuster added in the first selection operation is 2000~6000g / t, and the amount of bismuth inhibitor is 500~2000g / t.

5. The method for recovering copper from bismuth concentrate according to claim 4, characterized in that, The amount of pH adjuster added in the second selection process is 1000~3000g / t, and the amount of bismuth inhibitor is 100~1000g / t.

6. The method for recovering copper from bismuth concentrate according to claim 1, characterized in that, In step S5, the amount of copper collector added in the first scavenging operation is 10~50g / t, and the amount of copper collector added in the second scavenging operation is 5~20g / t.

7. The method for recovering copper from bismuth concentrate according to claim 1, characterized in that, The initial bismuth concentrate contains 2-3% copper and 30-35% bismuth.

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